Genetic evaluation of quantitative traits of rice (oryza sativa l.) by generation mean analysis

Abstract

Information on the inheritance of polygenic traits is worthful for planning and executing a breeding strategy leading to their genetic improvement. In order to study mode of gene action in rice for traits related to yield [days to 50 per cent flowering, plant height (cm), number of tillers per plant, length of panicle (cm), grain yield per plant (g), straw yield per plant (g) and harvest index (%)], two varieties of rice (Karjat 2 and Munga) were investigated. Direct and reciprocal crosses have been done between parents Karjat 2 and Munga and back crosses at the Experimental Farm of Agricultural Research Station, Karjat and Plant Biotechnology Centre, College of Agriculture, Dapoli, during kharif 2013 to kharif 2014. The additive x dominance model was significant for the traits viz;, plant height, number of tillers per plant, grain yield per plant and harvest index in cross II, while days to 50 per cent flowering in both crosses. The joint scaling test indicated that non allelic gene interactions additive x additive and dominant x dominant were more prominent and played significant role in inheritance of the several traits studied. The additive x dominant interaction were significant but had lesser preponderance for governing the traits and the duplicate type of epistasis was found for days to 50 per cent flowering, grain yield per plant and straw yield per plant (both crosses) and number of tillers per plant in cross I. More than one major gene group appeared to be involved for the expression of plant height while the remaining traits showed the presence of at least one major group of genes controlling their inheritance